Resumen de Niels Bohr’s First 1913 Paper: Still Relevant, Still Exciting, Still Puzzling
Many teachers like to introduce the Bohr atom toward the end of an introductory physics course. This is an excellent idea, given the historic importance of Bohr’s 1913 work, which provided the bridge from Planck’s quantized interaction of matter and radiation (1900) to the full theory of quantum mechanics (1925-28). Unfortunately, the version of the Bohr atom that appears in many textbooks and is no doubt often presented to students is more wrong than right and may leave both teachers and students wondering why, more than a hundred years later, it is still being taught. This “pedagogic” version postulates that an electron in a stationary state moves in a circular orbit with an angular momentum that is an integral multiple of h/2π (L = nh/2π = nħ)—ħ for the lowest-energy state, 2ħ for the next state, and so on. This picture of the hydrogen atom is wrong in two senses. First it doesn’t conform to our present understanding of the hydrogen atom. This, in itself, is not a reason to scrap it, for the historical development of quantum physics is certainly of interest. But second, it doesn’t conform to the essence of what Bohr actually did. That is a reason not to teach about circular orbits and L = nħ.
Much excellent scholarship has been devoted to Bohr’s 1913 work.3 This article is not intended to extend or enrich that scholarship. Rather, I want to draw the attention of teachers of introductory physics to the high points of Bohr’s classic first 1913 paper on the hydrogen atom and to clarify what in that paper is right and what is wrong (as well as what is weird). As I have pointed out in an earlier short communication,4 there is more right and less wrong than is widely recognized. As to what is weird, well, it is interesting.
